about 2 cups (grated and not packed) of your favorite vegan "cheese" that melts (such as Daiya, Tofutti, Sheese or Vegan Gourmet)

salt and freshly-ground pepper to taste

1 cup soy or nut milk, warmed

Preheat the oven to 350°F. Lightly oil a 2 qt. gratin dish or shallow casserole. Put on a pot of water to boil.

Heat the oil in a nonstick heavy skillet and add the onions and sage. Cook over medium heat, stirring often, until they soften and turn golden. OR, place the oil in a microwavable dish, add the onions and sage, cover and cook on full power for 8 minutes. (Shy of microwaves? Please read this.)

I use a mandoline slicer to cut the potatoes very thinly. You can also do this on an attachmentof your food processor. When the water boils, add some salt and add the potatoes and sweet potatoes. Stir the potatoes so that they don't clump together. When the water boils again, time for 1 minute.

Drain the potatoes and mix in a large bowl with the cooked onions and sage, and the parsley and garlic. Mix well.

Grate the "cheese". Spread 1/3 of the potatoes in the prepared pan. Sprinkle with salt and pepper and 1/3 of the "cheese". Repeat layering two more times. Pour the warm soy or nut milk over the gratin. Cover with foil. Bake 25 minutes. Remove foil and bake 25 minutes more. Let the gratin stand for 5 minutes before serving.